Model airplane



April 2, 1940. H. B. DANIEL MODEL AIRPLANE Filed March 25, 19:59

INVENTOR.

' 40 cording to. the'invention;

13 Claim.

This invention relates to model airplanes and is particularly intendedto provide such a device having a new and improved structure andarrangement of parts whereby a strong'and rigid n structure, which maybe manufactured and assembled in a new, improved and more simple:

manner, is provided. I

It is an object of the invention to provide a model airplane structurewhich is formed of preother associated parts to provide a complete I.structure.

A further object is to provide an improved fuselage structure which isformed by combining a plurality of elongated, pre-fabricated,- unitaryassemblages of parts, these assemblages being so ll constructed andconnected together that an improved fuselage is provided which has greatadvantages in strength and ease of assemblage over structures heretoforeprovided.

Other objects and features of novelty will 'be made apparent by thefollowing description and the annexed drawing, it being understood,however, that such description and drawing are only illustrative of theinvention, which is not limited thereby, or otherwise" than by theappended I 'olaims.' I

Referring to the drawing, in which similar reference numerals refer tolike parts,

Fig. 1 is a perspective view showing the meth- 0d of forming thefuselage of a toy airplane ac- I Fig. 2 is a slde view of a toyairplaneformed according to the invention;

' Fig. 3 isa sectional view taken on the line 3-4 I of Fig. 2;

. 4i Fig. 4- is a view, similar to Fig. aims showing a, modifiedfuselage structure; a

Fig. 5 is a perspective view illustrating the method according to theinvention of forming a wing structure; I

50 Fig. 6 is a front view of the wing structure after 1 assembly, and I.Y

' Fig. 'I is a sectionalview taken on the line l-- |v I of Fig. 6.

One of the principal features-of this invention f 1 58 is the new andimproved construction of' the masses MODEL AIRPLANE I I Henry BrentDaniel, Takoma Park, MIL, assignor to -Washington In stitute ofTechnology, Inc., Washington, D. (3., a corporation of DelawareApplication March 25, 1939, Serial No. 264,248

" attached together form a strong and rigid struc- (cLm-m a 1 fuselageof a model airplane and the method of formingand assembling the partswhich, together, constitute this new structure. According to theinvention, the fuselage is formed by uniting together a plurality ofelongated, pre-fabricated, 5 unitary side members, each of whichconstitutes a complete fuselage element, and which, when ture. Asillustrated in Fig; 1 .of the drawing, if a four-sided fuselage is to beprovided, two side 10 members I, 2, an upper member 3 and a bottommember 4 will be provided. Each of these is a complete, unitarystructure comprising longerons a and strut members b, these parts beingformed separately and united in any desired manner, as by gluing, or theentire side member being formed by a stamping operation.

These fuselage members are brought together in a loosely assembledrelation, as illustrated in Fig. 1, and a form or frame A may be used tono support the 'parts in this condition whilethe assembling-andattaching procedure is being car'- ried on. The parts are now united inany desired manner, it being preferred to connect them by gluing thelongerons together at the four cor- I ners of the assembly. Thecompleted fuselage structure will have the desired configuration and maybe covered with paper, fabric or other desired covering material.

It will be apparent that by reason of the building up of the fuselage byfour separate'and complete side members the fuselage will have greaterrigidity and strength than is provided by structures formed inaccordance with present prac- I tices. This is due primarily to the factthat at ll each of the corners of the fuselage there will be twolongerons instead of one. Further, and as illustrated in Figs. 3 and 4,the wood materials of abutting attached longerons are so chosen andarranged that the-grain, or wood formation, of do one longeron will notco-incide with that of the longeron whichabuts it, thereby providingincreased strength and rigidity. Each side and top. and bottom member ofthe fuselage, being a complete structural member in itself, will be Iable to resist greater forces than structures heretofore provided.

While a four-sided fuselage is illustrated in the I drawing anddescribed herein, it will be seen that the invention is applicable tothe construcv.tion of a fuselage having any number of sides, and that inany such case the advantages'o'f strength andrigidity inherent in thedisclosed structure will be provided.- I The rear end of the fuselage isreinforced b 'jfio" a cross-shaped block 2| which is positioned in theinterior thereof and the four cut-out corners of which are adapted toreceive the four longeron assemblies of the fuselage. An additionalbrace member 26 is positioned between this block and the rearmost end ofthe fuselage and adds additional strength to the assembly.

The invention also provides a new andimproved wing structure which isformed in a novel manner and which permits. simplified assembling toprovide a complete'wing structure. ,The-various parts of this new andimproved wing structure, and the manner of assembling the same, areillustrated in Figs. 5 and 6. Referringto these figures it will be seenthat the wing structure comprises a unitary, flat basestructurecomprising outer longitudinal members which are the leading edge stripl0 and the trailing edge strip II, the curved end members l2 and thetransverse bracing members IS. The transverse braces extend between theleading and trailing edge strips and are spaced along the length of thewing base member and adjacent-the midpoint of the base member twoclosely adjacent transverse members I3a are provided, one on each sideof the midpoint, for a purpose which will appear hereinafter. Additionalbracing of the frame is provided by spars II which extend longitudinallyfrom the struts l3a parallel to the edge members l0 and II andterminateat the outermost brace members l3, these spar members ll beingpreferably positioned closer to the leading edge member l0 than to themembers II. It will be seen that the intermediate longitudinal spars lldivide the transverse braces l3 and are attached thereto, although thesemay be connected by interfitting joints if desired. All of the describedmembers are connected together to provide a unitary member asillustrated in Fig. 5.

In order to provide a wing having the proper airfoil cross-section, Iprovide a plurality of ribs 20, these having flat base portions, whichare equal in length to the brace members l3, and curved upper surfaces,the curvature of such upper surfaces being made of such shape that whenthe ribs are placed on the braces l3, the cross-section of the wing isof proper airfoil shape. These ribs are adapted to be connected, as bygluing, to the upper surfaces of the transverse brace members 33 and,when so attached, extend upwardly therefrom at right angles to the planeof the wing base member, one strut member being provided for each braceI3, and these being of equal size and having corresponding curvature ofthe upper faces. For each of the two central brace members Ha I providerib members of generally similar configuration but the lower edges ofwhich are so formed that when these lower edges are attached to thebraces I3a the ribs will be inclined toward the nearest end of the wingbase, as illustrated in Fig. 5 and for a purpose which will appearherelnafter.

Formed in the upper, curved surface of the spaced rib members arerecesses 2| which are similarly shaped and positioned in each strut andwhich, when the struts are attached to the braces in the mannerdescribed, are adapted to receive longitudinally-extending spar members22, the same being of such length that each extends from one inclinedrib outwardly along the longitudinal length of the corresponding half ofthe wing, terminating in the aperture in the last rib member which, asillustrated in Fig. 5 is attached to the next to last transverse bracel3.

The apertures 2| and the longitudinal spars 22 are formed ofcorresponding section andv size whereby, when the spars 22 arepositioned within the" aligned apertures the upper surfaces thereof willbe flush with the upper surfaces of the rib members. The apertures 2|are preferably so positioned in the rib members that, when such membersare attached to the wing base in the manner described the apertures willbe po-' sitioned just above the intermediate longitudinal spar ll,whereby the two longitudinal members l4 and 22 co-operate to provideadditional strength and rigidity to the wing.

Additional bracing means are provided for each end of the wing and thesecomprise short strips 23 which extend in inclined position from theoutermost strut members 20 to the curved, end members l2. The inner endsof the braces 23 are adapted to be positioned in the apertures 2| of theoutermost rib members, while the lower faces of the outer ends thereofare beveled in order to provide a proper fit with the upper surfaces ofthe curved wing end members l2.

The wing parts are assembled by attaching the rib members 20 to theupper surfaces of the braces l3, those attached to the braces I20 beingdisposed in inclined position as described. The longitudinal spars 22are positioned in the apertures 21 and the braces 23 are arranged ininclined position between the outermost ribs 20 and the curved wing endmembers l2. These parts may all be connected in the described manner bygluing.

After assembly in the manner described the wing structure is out alongthe center line which is equidistant between the two ends of the wingand the two halves are folded upwardly toward each other, as illustratedin Fig. 6 until the ad- Jacent side wall faces of the inclined ribs I30abut, the parts being attached, as by gluing, in this position, a wingof angular configuration being thus formed. This wing structure isattached to the upper surface of the fuselage by any suitable means,rubber bands being used in the assemblage illustrated in the drawing.

Other parts of the toy airplane may be attached to the wing and fuselagestructure, these being the rudder, tail surface, propeller, landing gearand other elements, all as illustrated in Fig. 2 of the drawing. Ipropose to form all of these parts as unitary, assembled members,thereby facilitating the simple assembly of these parts. Certain of suchparts, as may be desired, may be covered with paper, fabric or othersuitable material.

While I have illustrated and described one form which my invention maytake it will be apparent to those skilled in the art that modifications,improvements and changes may be made therein without departing in anyway from the spirit or scope of the invention, for the limits of whichreference must be had to the appended claims.

I claim:

1. A fuselage structure for a model airplane comprising an elongatedbody of polygonal crosssection, certain of the oppositely-disposed sidesof said body being formed of separate, unitary frame members comprisingelongated edge members and transversely extending struts connecting saidedge members, said oppositely-disposed sides being spaced and connectedby separate. unitary frame members.

2. A fuselage structure according to claim 1, in which the frame memberswhich space and connect the oppositely-disposed sides are positionedinteriorly of the longitudinal edges of said sides.

3. A fuselage structure according to claim 1, in which the frame memberswhich space and connect the oppositely-disposed sides are positionedexteriorly of the longitudinal edges of said sides.

4. A fuselage structure for a model airplane, comprising an elongatedbody of polygonal crosssection, each of the sides of said fuselagestructure being a unitary frame member comprising elongated edge membersextending substantially throughout the length of the fuselage andtransversely extending strut members connecting said longitudinal edgemembers.

5. A fuselage for a model airplane, comprising an elongated body ofpolygonal c1 'oss-section, each of the sides of said body being aseparate unitary structure comprising edge members extendinglongitudinally of the body and bracing members extending between saidedge members and connected thereto.

6. A wing for a model airplane comprising a flat frame structure havingspaced leading and trailing edge members extending longitudinallythereof, a spar member extending parallel to and between said edgemembers, a plurality of spaced brace members connecting the leading andtrailing edge members and intersecting the intermediate spar member, andseparate rib members attached to the upper surfaces of the brace membersand extending above said flat frame structure and being so shaped thatwhen so attached the cross-section of the wing is substantially ofairfoil shape.

'7. A wing for a model airplane according to claim 6, in which each ofsaid rib members has an aperture formed in the upper surface thereof,which apertures are aligned longitudlnallyof the associated framestructure, and a spar member received in said aligned apertures.

8. A wing for a model airplane according to claim 6, in which aperturesare formed in the upper surfaces of the rib members approximately abovethe intermediate spar member of the flat frame structure, whereby asecond spar member positioned in said apertures is disposedsubstantially above said intermediate spar member.

9. A wing for a model airplane comprising two flat frame structureswhich are arranged in end to end relation and which form a dihedralangle at their meeting ends, each of said frame structures comprisingspaced leading and trailing edge members extending longitudinallythereof. braces connecting said edge members, and spaced rib membersattachedto the upper surface of said braces and extending above the flatframe structure to which the are attached and defining with the framestructure a cross section of substantially air foil form, the ribmembers at the meeting ends of the frame structures being disposed inface-to-face engagement.

10. A wing for a model airplane according to claim 9, in which the ribmember at the end of each frame structure adjacent the end of the otherframe structure is inclined with respect to the attached framestructure.

11. A wing for a model airplane according to claim 9, in which each ofsaid frame structures comprises in addition a spar disposed between saidedge members and extending parallel thereto and intersecting and beingconnected to said braces.

12. A wing for a model airplane comprising a flat frame structure havingspaced leading and trailing edge members extending longitudinallythereof, a plurality of spaced brace members connecting said edgemembers, curved end members connecting said edge members at each end ofsaid frame structure and being disposed outwardly from the last of saidbrace members, rib members attached respectively to the upper surfacesof said brace members and extending above the plane of said structureand being so shaped that when so attached the wing has a substantiallyairfoil cross-section, an elongated spar member arranged parallel tosaid edge members and connected directly to the upper portions of saidrib members and extending along the wing toward the outer end thereof tothe last of said rib members, and inclined reinforcing spars each ofwhich is connected at its one end to the upper portion of the last ofsaid rib members at one end of said wing and at its other end to theupper surface of the adjacent one of said curved members.

13. A wing for a model airplane comprising a flat frame structure havingspaced leading and trailing edge members extending longitudinallythereof, a plurality of spaced brace members connecting the leading andtrailing edge members, and rib members attached to the upper surfaces ofsaid brace members and extending above the flat frame structure andbeing so shaped as to cause the cross-section of the wing to be HENRYBRENT DANIEL.

